Leaks are also likely on the turbo inlet (unless I missed that). That plastic pipe is 15+ years old and gone thru numerous heat cycles. There are good silicone replacements that do NOT require the IM to come off/be loosened - I did it.
Just to clarify...for those that may find this:
BCS = Boost Control Solenoid, aka DUTY SOLENOID Valve, per Subaru.
BOV = Blow-off Valve, aka BPV = Bypass Valve (not identical functioning parts, but similar)